Various applications that employ plastics (e.g., cellulosics) could be enhanced if the plastics could exude a pleasing or appropriate fragrance based on their end use.
U.S. Pat. No. 5,460,787 discloses a scented card which includes a fragranced thermoplastic material. The process of producing the scented card includes, providing a dry particulate thermoplastic material, blending a chemical flowing agent and at least one fragrance into the thermoplastic material to form a mixture, and heating the mixture in a thermoplastic extruder. The chemical flowing agent creates gas pockets within which the fragrance is trapped.
U.S. Pat. No. 3,661,838 discloses a scented plastic composition having a porous, finely divided silica powder having absorbed thereon a liquid scent emitting substance that is contained within the plastic material. The patent states that previous attempts have been made to dissolve a liquid scent-emitting substance into the liquid plasticizer, and a mixture of the scent emitting substance and plasticizer is subsequently added to the resin followed by heating and solidification. According to the patent, the liquid scent emitting substances which are dissolved in the plasticizers under known processes evaporate or decompose due to the processing heat applied during the time of the heat melting process, and do not provide sufficient fragrance intensity.
U.S. Published Patent Application No. 2003/0072733 discloses cellulose acetates as absorbent materials in a process for absorbing moisture and/or malodor in providing a fragrance to the surrounding ambience. The cellulose acetate and cellulose butyrate is not plasticized nor is a process provided for providing a fragrance plastic product.
U.S. Pat. No. 6,703,012 discloses compositions containing fragrances and powdered water-soluble polymers that are processed into toilet blocks. Polyvinyl acetates and mixtures of polyvinyl alcohol in partially hydrolyzed polyvinyl acetate are used. The fragrance is introduced into the extruder and the time of extruding the polymer.
U.S. Pat. No. 4,492,644 discloses and ethylene and vinyl acetate copolymer used with a perfume. The ethylene-vinyl acetate copolymer is pre-formed into granules having a diameter of about one to ten millimeters. A perfume and granulated copolymer are mixed at a temperature in a range of about ten degrees Celsius. This patent states that the granulated ethylene-vinyl acetate copolymer containing the perfume may increase in volume according to the amount of the perfume impregnated and absorbed therein, but it will never exhibit a softening effect. The '644 patent is not directed to cellulose acetate esters, such as cellulose acetate, cellulose acetate butyrate, and cellulose acetate propionate.
U.S. Pat. No. 4,598,006 discloses a method for impregnating a thermoplastic polymer with a fragrance by dissolving the fragrance in a volatile swelling agent maintained at or near super-critical conditions for the volatile swelling agent, swelling the thermoplastic polymer by contacting it at or near the supercritical conditions of the volatile swelling agent, then reducing the pressure so that the volatile swelling agent diffuses out of the thus impregnated thermo-plastic polymer. The thermoplastic polymer swells upon contact with the fragrance at or near supercritical conditions. The contacting permits rapid diffusion of the impregnation material into the polymer. Swelling agents include carbon dioxide, ethylene and nitrous oxide.
There is a need for imparting fragrance to cellulosics, including cellulose acetate, cellulose acetate butyrate, and cellulose acetate propionate, that has sufficient fragrance intensity while minimizing the amount of fragrance used, and also avoids compromising the plastic by the addition of silica materials or the addition of extraneous components to create formation voids within the plastic. There is a further need to optimize the fragrance of a cellulosic either by process improvements or additives so that end-use products that are made of the fragranced cellulosic have an optimal fragrance amount and are appealing to the consumer.